The main scientific and practical results are given. The factors are established concerning the determination of the efficiency of drilling-and-blasting preparation of ore mass for the underground block leaching. The parameters of this technology are substantiated, which ensure rational use, protection of the subsoil and the environment, as well as environmental and technological safety. The methods of summarizing, analyzing and assessing practical experience and scientific achievements in the field of theory and practice of leaching metals from ores, drilling-and-blasting fracture of solid media, continuum mechanics, mathematical statistics, as well as the study of wave processes based on the standard and new methods of leading specialists of the developed mining countries with participation of the authors. Blast parameters are substantiated taking into account the size of the average linear piece of the exploded ore mass in the compensatory slot, the area of the emanating surface and safety of the protected objects. It was shown that the degree of fragmentation equal to 1.2–1.3 is one of the main parameters, by which the length of the section consisting of layers (rows) was calculated, after breaking of which the fragmentation of the compensatory ore mass becomes limiting. Technology of the underground block leaching is described, which includes the maximum use of existing mine workings for creation of irrigation horizons of leaching and capturing product solutions. The value of metal extraction from ores by technologies is recommended, which is in power dependence on the average linear size of the piece of the blasted ore mass, and reaches maximum values at its grain size grade –25+0 mm. This allows to select the rational parameters of the drilling-and-blasting preparation of ores with a given crushing quality, to enhance the infiltration of product solutions and to extract over 70 % of useful components (maximum deviation of the actual composition of the ore grade –25+0 is 7.2 %). It is proved that when not good ore deposits are involved in the production (for conventional technologies), their raw material base can be increased by 1.4–1.6 times.
Read in №8 of 2019 year "Improvement of the Efficiency of Drilling and Blasting Preparation of Ore Mass for the Underground Block Leaching"
29 авг 2019